3,623 research outputs found
Combining Theory and Practice in the Teaching of Science Institutions: A Collaborative Program between the City University of New York and the American Museum of Natural History
The National Science Education Standards contain several mandates that share the use of alternative and creative experiences in the teaching of science at all levels. An important feature of these standards is the call for learning settings and environments different from the traditional classroom in order to enhance student interest and participation in the learning process. New York City is rich in institutions that are ideal for the implementation of effective science teaching through the use of informal resources. This article uses the American Museum of Natural History as a prime example of this
SOLUBILIZATION OF P-ALKYLPHENOLS IN PLURONICS F-68 AND F-127 MICELLES: PARTITION COEFFICIENTS AND EFFECT OF SOLUTE ON THE AGGREGATE STRUCTURE
Indexación: Web of Science; Scielo.The partition of a series of substituted phenols between water and polymer micelles formed by Pluronic F-68 and F-127 has been studied. The formation of micelles by these block copolymers has been evidenced by steady-state fluorescence and dynamic light scattering. The data show that micelles and larger aggregates are formed above the critical micelle concentration. In presence of p-alkylphenols a micelle rearrangement occurs that leads to the formation of just one and large aggregate. This effect depends both on polymer and phenols structures. The partition coefficients and the standard free energies of transfer from the aqueous to the micellar phases were determined. The incremental free energy for a methylene group are 2.88 kJ mol-1 and 1.65 kJ mol-1 for F-127 and F-68, respectively. This difference is explained in terms of the core sizes that are determined by the length of the PPO block.http://ref.scielo.org/xfqmx
Identification of novel post-transcriptional features in olfactory receptor family mRNAs.
Olfactory receptor (Olfr) genes comprise the largest gene family in mice. Despite their importance in olfaction, how most Olfr mRNAs are regulated remains unexplored. Using RNA-seq analysis coupled with analysis of pre-existing databases, we found that Olfr mRNAs have several atypical features suggesting that post-transcriptional regulation impacts their expression. First, Olfr mRNAs, as a group, have dramatically higher average AU-content and lower predicted secondary structure than do control mRNAs. Second, Olfr mRNAs have a higher density of AU-rich elements (AREs) in their 3'UTR and upstream open reading frames (uORFs) in their 5 UTR than do control mRNAs. Third, Olfr mRNAs have shorter 3' UTR regions and with fewer predicted miRNA-binding sites. All of these novel properties correlated with higher Olfr expression. We also identified striking differences in the post-transcriptional features of the mRNAs from the two major classes of Olfr genes, a finding consistent with their independent evolutionary origin. Together, our results suggest that the Olfr gene family has encountered unusual selective forces in neural cells that have driven them to acquire unique post-transcriptional regulatory features. In support of this possibility, we found that while Olfr mRNAs are degraded by a deadenylation-dependent mechanism, they are largely protected from this decay in neural lineage cells
A 'virtuous circle' of illicit markets? Smuggling and colonial state building in the Italian interwar Dodecanese
Can illegal markets play a role in a state’s conscious strategies and efforts to establish and further order? Are there conditions under which law enforcement takes second place to wider considerations of national interest? The relationship between state policy and illicit economic activity is typically understood as an oppositional one: beyond a sense of lawlessness, illegal markets exist as a threat to the state’s economic and fiscal interests. In fact, our contemporary understanding of illegal markets is underpinned by the understanding of ‘organised crime’, which is often equally seen as inherently oppositional to a state’s claim on law and order over its territory. Contemporary discourses leave very little margin for a consideration of the relationship between state policy makers and regulators as anything other than conflictual
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